SAFIR-I: Design and Performance of a High-Rate Preclinical PET Insert for MRI

Sensors

Jannis Fischer¹  Jan Debus¹  Parisa Khateri¹  Volker Commichau¹  Lubomir Djambazov¹  Günther Dissertori¹  Ulf Röser¹  Christian Ritzer¹  Pascal Bebié¹  Mikiko Ito¹  Agnieszka Zagozdzinska-Bochenek¹  Robert Becker¹  Werner Lustermann¹  Michael Ritzert²  Peter Fischer²  Matthias T. Wyss³  Afroditi Eleftheriou³  Bruno Weber³  Geoffrey Warnock³  Charalampos Tsoumpas⁴ 

[1] Institute for Particle Physics and Astrophysics, ETH Zürich, 8093 Zürich, Switzerland;Institute of Computer Engineering, Heidelberg University, 69120 Heidelberg, Germany;Institute of Pharmacology and Toxicology, University of Zürich, 8057 Zürich, Switzerland;Leeds Institute of Cardiovascular and Metabolic Medicine, University of Leeds, Leeds LS2 9JT, UK;

关键词: PET detector;    PET insert;    MRI;    preclinical PET/MRI;    dynamic PET/MR imaging;    high frame rates;   

DOI  :  10.3390/s21217037

来源: DOAJ

【 摘 要 】

(1) Background: Small Animal Fast Insert for MRI detector I (SAFIR-I) is a preclinical Positron Emission Tomography (PET) insert for the Bruker BioSpec 70/30 Ultra Shield Refrigerated (USR) preclinical 7$\mathrm{T}$ Magnetic Resonance Imaging (MRI) system. It is designed explicitly for high-rate kinetic studies in mice and rats with injected activities reaching 500$\mathrm{M}$$\mathrm{Bq}$, enabling truly simultaneous quantitative PET and Magnetic Resonance (MR) imaging with time frames of a few seconds in length. (2) Methods: SAFIR-I has an axial field of view of $54.2$$\mathrm{m}$$\mathrm{m}$ and an inner diameter of 114$\mathrm{m}$$\mathrm{m}$. It employs Lutetium Yttrium OxyorthoSilicate (LYSO) crystals and Multi Pixel Photon Counter (MPPC) arrays. The Position-Energy-Timing Application Specific Integrated Circuit, version 6, Single Ended (PETA6SE) digitizes the MPPC signals and provides time stamps and energy information. (3) Results: SAFIR-I is MR-compatible. The system’s Coincidence Resolving Time (CRT) and energy resolution are between separate-uncertainty $209.0\left(3\right)$$\mathrm{p}$$\mathrm{s}$ and separate-uncertainty $12.41\left(02\right)$ Full Width at Half Maximum (FWHM) at low activity and separate-uncertainty $326.89\left(12\right)$$\mathrm{p}$$\mathrm{s}$ and separate-uncertainty $20.630\left(011\right)$ FWHM at 550$\mathrm{M}$$\mathrm{Bq}$, respectively. The peak sensitivity is ∼$1.6$. The excellent performance facilitated the successful execution of first in vivo rat studies beyond 300$\mathrm{M}$$\mathrm{Bq}$. Based on features visible in the acquired images, we estimate the spatial resolution to be ∼2$\mathrm{m}$$\mathrm{m}$ in the center of the Field Of View (FOV). (4) Conclusion: The SAFIR-I PET insert provides excellent performance, permitting simultaneous in vivo small animal PET/MR image acquisitions with time frames of a few seconds in length at activities of up to 500$\mathrm{M}$$\mathrm{Bq}$.

【 授权许可】

Unknown